<!DOCTYPE html>
<html>
<head>
    <title>动态文本框</title>
</head>
<body>
    <button onclick="addInput()">添加文本框</button>
    <div id="container"></div>

    <script>
        let count = 0;
        function addInput() {
            const container = document.getElementById('container');
            const newInput = document.createElement('input');
            newInput.type = 'text';
            newInput.placeholder = `文本框 ${++count}`;
            container.appendChild(newInput);
            container.appendChild(document.createElement('br'));
        }
    </script>
</body>
</html>